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// SPDX-License-Identifier: GPL-2.0
/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Thomas Spatzier (tspat@de.ibm.com)
*
* Derived from "arch/i386/kernel/sys_i386.c"
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/s390
* platform.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/unistd.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/string.h>
#include <linux/thread_info.h>
#include <linux/entry-common.h>
#include <asm/ptrace.h>
#include <asm/vtime.h>
#include "entry.h"
/*
* Perform the mmap() system call. Linux for S/390 isn't able to handle more
* than 5 system call parameters, so this system call uses a memory block
* for parameter passing.
*/
struct s390_mmap_arg_struct {
unsigned long addr;
unsigned long len;
unsigned long prot;
unsigned long flags;
unsigned long fd;
unsigned long offset;
};
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
{
struct s390_mmap_arg_struct a;
int error = -EFAULT;
if (copy_from_user(&a, arg, sizeof(a)))
goto out;
error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
out:
return error;
}
#ifdef CONFIG_SYSVIPC
/*
* sys_ipc() is the de-multiplexer for the SysV IPC calls.
*/
SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
unsigned long, third, void __user *, ptr)
{
if (call >> 16)
return -EINVAL;
/* The s390 sys_ipc variant has only five parameters instead of six
* like the generic variant. The only difference is the handling of
* the SEMTIMEDOP subcall where on s390 the third parameter is used
* as a pointer to a struct timespec where the generic variant uses
* the fifth parameter.
* Therefore we can call the generic variant by simply passing the
* third parameter also as fifth parameter.
*/
return ksys_ipc(call, first, second, third, ptr, third);
}
#endif /* CONFIG_SYSVIPC */
SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
{
unsigned int ret = current->personality;
if (personality(current->personality) == PER_LINUX32 &&
personality(personality) == PER_LINUX)
personality |= PER_LINUX32;
if (personality != 0xffffffff)
set_personality(personality);
if (personality(ret) == PER_LINUX32)
ret &= ~PER_LINUX32;
return ret;
}
SYSCALL_DEFINE0(ni_syscall)
{
return -ENOSYS;
}
void do_syscall(struct pt_regs *regs)
{
unsigned long nr;
nr = regs->int_code & 0xffff;
if (!nr) {
nr = regs->gprs[1] & 0xffff;
regs->int_code &= ~0xffffUL;
regs->int_code |= nr;
}
regs->gprs[2] = nr;
nr = syscall_enter_from_user_mode_work(regs, nr);
/*
* In the s390 ptrace ABI, both the syscall number and the return value
* use gpr2. However, userspace puts the syscall number either in the
* svc instruction itself, or uses gpr1. To make at least skipping syscalls
* work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here
* and if set, the syscall will be skipped.
*/
if (!test_pt_regs_flag(regs, PIF_SYSCALL_RET_SET)) {
regs->gprs[2] = -ENOSYS;
if (likely(nr < NR_syscalls))
regs->gprs[2] = current->thread.sys_call_table[nr](regs);
} else {
clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
}
syscall_exit_to_user_mode_work(regs);
}
void noinstr __do_syscall(struct pt_regs *regs, int per_trap)
{
add_random_kstack_offset();
enter_from_user_mode(regs);
regs->psw = S390_lowcore.svc_old_psw;
regs->int_code = S390_lowcore.svc_int_code;
update_timer_sys();
local_irq_enable();
regs->orig_gpr2 = regs->gprs[2];
if (per_trap)
set_thread_flag(TIF_PER_TRAP);
for (;;) {
regs->flags = 0;
set_pt_regs_flag(regs, PIF_SYSCALL);
do_syscall(regs);
if (!test_pt_regs_flag(regs, PIF_SYSCALL_RESTART))
break;
local_irq_enable();
}
exit_to_user_mode();
}
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